Apparatus for distributing and drying uniform interior coatings in collapsible tubes



J ne 1952 F. REMINGTON EI'AL 2,599,721

APPARATUS FOR DISTRIBUTING AND DRYING UNIFORM INTERIOR COATINGS IN COLLAPSIBLE TUBES Filed June 25, 1949 2 SHEETS-SHEET l F. OR DISTRIBUTING REMINGTON ETAL APPARATUS F 2,599,721 AND DRYING UNIFORM LLAPSIBLE TUBES June 10, 1952 zjINTERIOR COATINGS IN CO 2 SI-IEETS-SHEET 2 Filed June 25, 1949 Patented June 10, 1952 APPARATUS FOR DI INT 'COLLAPSIBLE TUB IN G UNIFORM Frederic Remington,

STRIBUTING AND DRY- EERIOR COATINGS IN Elizabeth, and Richard A. Tartaglia, East Orange, N.

J assignors to Peerless Tube Company, Bloomfield, N. J a corporation of New Jersey Application June 25, 1949, Serial No. 101,466

This application is a continuation in part of our co-pending application, Serial No. 766,368, filed August 5, 1947, and the invention relates to the interior coating that is applied to certain types of collapsible tubes to prevent contamination by the metal of the tube of the substance which may be subsequently packaged in the tube.

In the manufacture of collapsible tubes, it is customary to extrude a slug of metal into a tube having one end open and the other end shaped into a shoulder and neck to be later threaded for the reception of a cap, and a liquid wax coating or lacquer is applied to the interior surfaces of the tube. One method and machine for applying such coatings to collapsible tubes is described and claimed in United States Patent No. 2,420,620, dated May 13, 1947, wherein the tubes are mounted in vertical position with their open ends lowermost on a suitable carrier, such as an endless chain, by which the tubes are moved past a liquid-injecting mechanism which injects a jet of liquid upwardly into the tubes. The tubes are then permitted to drain by gravity, the liquid dripping off the lower edges of the open ends of the tubes. During this operation, the liquid has a tendency to build up on the lower portions of the tubes so that the thickness of the coatings is much greater at these portions of the tubes than at the upper or head ends thereof, and a bead of liquid sometimes forms on the edges of the tubes at the lower open ends thereof.

A prime object of the invention is to provide a novel and improved machine for obtaining a coating of substantially uniform thickness throughout the length of a tube, especially on the interior of the tube; and a more particular object is to provide in such a machine novel and improved means for holding and conveying a tube which bears a fluent coating that has been drained from an end of the tube, in such a manner as to cause the coating material on the tube to fiow by gravity toward the other end of the tube.

A further object is to provide a machine of the character described which shall also include means for rapidly and completely drying the coating on the interior of a tube while it is being held in a position to cause the coating material on the interior of the tube to flow from one end toward the other end of the tube.

A further object is to provide apparatus for drying interior coatings in collapsible tubes which shall comprise a novel and improved construction and combination of a preliminary drying chamber, a final drying chamber, means for 6 Claims. (01. 118-66) conveying the tubes through said preliminary and final drying chambers, means for heating the final drying chamber, means for. circulating the heated air through the final drying chamher and from said final drying chamber throughout the preliminary drying chamber so as to effect rapid and efficient drying of the coatings on the tubes.

Other objects are to provide in apparatus of the character above described, novel and improved means for automatically discharging or ejectin the tubes from the holding means after they have been dried; and. to obtain other advantages and results that will be brought out by the following description in conjunction with the accompanying drawings in which Figure 1 is a side elevational view of apparatus constructed in accordance with the invention and for obtaining and drying uniform interior coatings in collapsible tubes;

Figure 2 is an end elevational view approximately from the plane of the line 2-2 of Figure 1 with portions broken away and shown in section;

Figure 3 is a horizontal sectional view approximately on the plane of the line 3-3 of Figure 1;

Figure 4 is a vertical longitudinal sectional view through the apparatus approximately on the plane of the line 4-4 of Figure 3;

Figure 5 is an enlarged fragmentary combined side elevational and sectional view approximately on the plane of the line 5-5 of Figure 3; and

Figure 6 is an enlarged fragmentary sectional view approximately on the plane of the line 66 of Figure l and showing the manner of discharging the collapsing tubes from the holding means.

Specifically describing the illustrated embodiment of the invention, the collapsible tubes to be treated are designated by the reference character A, and each comprises a tubular portion l the inner surface of which has a coating 2 of suitable material in liquid or semi-liquid form, the thickness of which at the open end of the tube is greater, as indicated at 3, than at the other portions of the tube as theresult of the previous draining operation to which the tube has been subjected, for example as described in our above-mentioned Patent No. 2,420,620. In accordance with the invention, this accumulation of fluent coating liquid is caused to now by gravity toward the head end 4 of the tube so as to make the thickness of the coating substantially uniform throughout the length of the tube;

and during said flow of the coating material,

'jdrying chambers. a plurality of reaches running form thickness. conveyor B through thepreliminary drying chamthe coating layer is subjected to a drying atmosphere.

For this purpose the tubes to be treated are moved by an endless conveyor B, first through a preliminary drying chamber C, then through a final drying chamber D upon emergence from which the tubes are preferably automatically discharged from the conveyor into a suitable receptacle or upon another conveyor by which the tubes are carried to the site of. the next operation to be performed on the tubes, for example trimming of the open end of the tube and threading of the neck of the tube. The preliminary drying chamber C has a common inlet and outlet opening at one end thereof in spaced relation to and facing the inlet and outlet openings 6 and I, respectively, of the final drying chamber D, and preferably the collapsible tubes are applied to and removed from the conveyor at the respective stations E and F in the space between the Preferably the conveyor has I through each of the preliminary and final heating chambers and is shown as comprising a chain mounted on Y sprockets 8 which in turn are journaled on suitable bearing brackets 9 in the drying chambers, and a pair of idler sprockets ID guide one reach of the chain from the outlet of the preliminary drying chamber to the inlet 6 of the final drying chamber. As shown, there are two reaches of the conveyor chain in the preliminary drying chame ber and four reaches in the final drying chamber;

The conveyor may be driven in any suitable manner, for example through a beveled gear G mounted on the shaft H carrying the sprocket 8,

said gear G meshing with a beveled pinion I driven. through speed reducing mechanism K an electric motor L.

. For mounting the collapsible tubes on the com veyor, a plurality of cradles are provided, each for one collapsible tube and each including a tubular holder ll of a diameter to freely receive a collapsible tube, said holder being pivotally mounted at l2 between the vertical arms l3 of "a. bracket I4 the base of which is secured to the 'conveyor chain in any suitable manner.

As shown, each Vertical arm l3 has its lower end connected to a base l5 which is attached to the chain by one of the pins l6 by which the links H; of the chain are pivotally connected together. Preferably the chain has rollers 18 thereon riding upon a track [9 for supporting the weight of the tubes and brackets between the various sprockets.

The tubular holder is mounted to swing in vertical planes and the pivot I2 is so located that gravitational action will maintain the holder in substantially vertical position as shown in Figures 3,, 4 and 5, and the arms l3 are formed with seats 20 for the head end of a collapsible tube, so that when a tube is inserted into the holder, the head end of the tube will rest on said seats, as best shown in. Figure 5, in which position any excess coating, liquid may drain through the open necks of the tubes.

In operation of the. machine, as the tubes are removed from the coating and draining machine,

one tube is inserted in each holder H at station E in an upside down position, that is, with the head end lowermost, so that the accumulated coating at the bottom end of the tube will fiow by gravity toward the head end, thereby tending to spread the liquid into a coating layer of uni- The tube is then carried by the 4 ber C and thence through the final drying chamber D.

At the end of the drying operation and upon emergence of the dried tubes from the outlet 1 of the final drying chamber D, the tubes may be removed from the holders in any, suitable manner, but preferably the holders H are automatically tilted at station F through an angle of less than ninety degrees as shown in Figure 6, so that collapsible tubes may fall by gravity out of the holders into a receptacle or upon another conveyor. Any suitable means may be used for tiltingthe holders, but as shown in Figures 1, 3 and 6, a pair of tilting elements are provided to be engaged by" the tubular holders at opposite sides thereof and above and below the pivotal mounting lzr As shown, these tilting elements comprise rollers 24 and 25 mounted to rotate on vertical axes on the respective brackets 26 and 2'! which are illustrated as secured to the juxtaposed-walls of the drying chambers C and D; and one roller is mounted at one side of the vertical plane of the path of'movement of the holders and below the pivotal mounting l2 thereof, while the other roller is mounted at the other side of said plane and above said pivotal mounting, as best shown in Figures 1 and 6, so that as each tube holder moves past the rollers, said rollers will cooperate to tilt the holder outwardly to clear the head ends of the collapsible tubes from the seats 2!] on the brackets and permit gravitational discharge of the tubes from the holders as best shown in Figure 6; After the holders have passed the rollers 24 and .25 the holders will be. swung by gravity into their normal vertical position ready to receive other tubes.

In accordance with the invention, in order to rapidly and efficiently dry the coatings on the tubes, means is provided for circulating air through the drying chambers and for heating said drying chambers in a novel and improved manner. As shown, an. air duct 28 is mounted at the top of the final drying chamber D so as to clear the tops of the collapsible tubes on the conveyor, and asimilar air duct 29 is located at the bottom of said drying chamber beneath the conveyor. Each air duct, has a plurality of apertures 3| in its inner wall for establishing communication between the air ducts and the drying chamber. Air is caused to circulate from the upper air, duct through the drying chamber over the collapsible tubes therein, thence through the lower air duct and then back to the upper air duct, by any suitable mechanism, for example a centrifugal pump 30 driven by an electric motor; and fresh air is drawn into the chamber through the openings 6 and 1.

For heating the air that circulates through the drying chamber, a plurality of electric heaters 32 preferably of the strip type are located between the upper air duct 28 and the tops of the collapsible tubes in the drying chamber; and a plurality of similar heaters 33 are disposed below the conveyor B and above the lowerair duct 29. These heaters may be mounted in any suitable manner but are shown asv fastened on horizontal skeleton-like frames 34 that are mounted on the walls of the drying chamber. With this construction, it will be observed that during the operation of the pump 30,. continuous currents of heated air will be caused to flow from the upper air duct 28 downwardly and into contact with the collapsible tubes in the drying chamber and the air will also be heated by the heaters 33 as it enters the lower air duct 29. At the same time, the heaters will continually radiate heat into the drying chamber so that a high and uniform temperature may be maintained in the final drying chamber D.

Some of the heat from the drying chamber is also utilized for heating the preliminary drying chamber C wherein the larger portion of the moisture and volatile components of the coating material is removed from the tube coatings. It is desirable that the temperature in the preliminary drying chamber be substantially less than that in the final drying chamber, and as shown upper and lower air ducts 35 and 36 are disposed above and below the conveyor in the preliminary drying chamber in a manner similar to the arrangement of the upper and lower ducts 28 and 29 in the final drying chamber D. Hot air is withdrawn from the final drying chamber D through a pipe 31 by a motor driven pump 38 which forces said air through a pipe 39 into the upper air duct 35 from which the air is caused to flow downwardly over the collapsible tubes and thence into the lower air duct 36 from where the moisture laden air is withdrawn by another pump 40 and exhausted into the atmosphere through a pipe 4|. The temperature of the air entering the preliminary drying chamber may be of the order of 150. This air flowing over the collapsible tubes picks up a large quantity of moisture and other volatile materials from the coating on the tubes and the moisture laden air is quickly evacuated from the chamber. To regulate the temperature of the air entering the preliminary drying chamber and also to admit fresh air when desired, an auxiliary air inlet 42 controlled by a valve 43 may be inserted in the pipe 31 between the final drying chamber and the pump 38. With this arrangement, the operator of the apparatus may modify the condition of the air entering the preliminary drying chamber in accordance with varying atmospheric conditions and difierent coating materials.

While the temperature may be controlled in the main drying chamber D in any suitable manner, it is preferable to connect the electric heaters in circuit so that they may be cut in or out of the circuit individually or in groups and suitable thermostatic controls may be utilized.

The passage of the coated tubes through the preliminary drying chamber conditions the coating for the final drying operation which may be carried on at a temperature about 400 F. The recirculation of the heated air in the final drying chamber and the useof some of the heated air in said chamber for preliminary drying of the coatings enables eilicient and economic utilization of heat and power makes it possible to perform the drying operations more thoroughly, in less time, and at less cost than has been possible heretofore.

While we have shown and described the apparatus as embodying certain details of construction, it will be understood that this i primarily for the purpose of illustrating the new preferred embodiment of the invention and that the structure of the machine may be widely modified and changed within the spirit and scope of the invention.

We claim:

1. A machine for causing distribution of fluent coatings on tubes, comprising a traveling conveyor, a plurality of cradles on said conveyor each including a bracket connected to said conveyor, a holder pivotally mounted on a transverse horizontal axis on each of said brackets to swing by gravitational action into vertical position, a seat on said bracket beneath the lower end of each holder, each of said holders to slidably receive within itself a collapsible tube with one end resting on said seat, and means for tilting said holders through an angle of less than ninety degrees to swing the lower end of each holder away from the corresponding seat and cause said tubes to slide by gravitational action out of said holders through the lower ends thereof.

2. The machine as defined in claim 1, wherein the last-named means comprises two elements mounted respectively at opposite sides of the path of movement of said tubes on said conveyor and above and below said pivotal mounting of the tubular holders on the brackets, to be engaged by and swing said holders about their said pivotal mountings a the holders are moved past said elements.

3. Apparatus for causing distribution and drying of a fluent coating on tubes after the excess of the coating material has been drained from one end of the tube, said apparatus comprising a main drying chamber, a traveling conveyor movable through said drying chamber, means for removably mounting said tubes on said conveyor with said end thereof uppermost so that said coating will flow by gravity toward the other end of the tube and with both ends open for circulation of air through the tube, air ducts in said chamber above and below said conveyor and opening into said chamber, heaters within said chamber between said air ducts and said conveyor, and means for causing circulation of air through a continuous circuit from one of said air ducts, through said chamber to the other duct and thence to the first-mentioned duct.

4. Apparatus as defined in claim 3 with the addition of a preliminary drying chamber through which said conveyor also moves and through which said tubes are conveyed before they enter said main drying chamber, and means for causin circulation of heated air from said main drying chamber through said preliminary drying chamber and thence to the atmosphere, the last-named means including upper and lower air ducts opening into said preliminary drying chamber above and below said conveyor respectively, a pipe connection between the said upper air duct and said main drying chamber, an outlet to the atmosphere from said lower duct, and pump means for forcing air from said main drying chamber through said upper duct, then through said preliminary drying chamber to said lower duct and thence to the atmosphere.

5. A machine for causing distribution of fluid coatings on the interior surfaces of tubes, comprising a conveyor and a normally vertical tubular holder of an internal diameter greater than the external diameter of a coated tube to loosely receive a coated tube in vertical position, means pivotally mounting said holder on said conveyor to swing on a horizontal axis perpendicular to its own axis, a seat carried by said conveyor beneath the lower end of said holder to be engaged by the lower end of the tube and to hold said tube normally against sliding out of said holder, and means for swinging said holder from said normal vertical position through an angle of less than ninety degrees (90) to move the lower end of the holder and the lower end of the tube away from said seat and cause said tube to fall from said holder by action of gravity.

6. A machine as defined in claim 5, wherein the last-namedmeans for" swinging the holder "UNITED SIIZATES PATENTS from said vertical position comprises an element Number Name Date projecting into the path of movement of said 2088 542 Westm July 27, 1937 holder on the conveyor to be engaged by the 5 Albflght 1943 holder as it is moved past, said element. 5 2:38-9459 Remark et aL 1945 FRED-ERIC REMINGTON 2,419,484 Danziger Apr. 22, 1947 RICHARD TARTAGLIA- 2,420,620 Remington et al- May'13, 1947 REFERENCES CITED 2,489,371 Friden et a1. Nov. 29, 1949 The following references are of record in the 1 file of this patent: 

